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We present time-series, high-resolution optical spectroscopy of the eccentricT Tauri binary TWA 3A. Our analysis focuses on variability in the strength andstructure of the accretion tracing emission lines H alpha and He I 5876A. Wefind emission line strengths to display the same orbital-phase dependentbehavior found with time-series photometry, namely, bursts of accretion nearperiastron passages. Such bursts are in good agreement with numericalsimulations of young eccentric binaries. During accretion bursts, the emissionof He I 5876A consistently traces the velocity of the primary star. Afterremoving a model for the system's chromospheric emission, we find the primarystar typically emits ~70% of the He I accretion flux. We interpret this resultas evidence for circumbinary accretion streams that preferentially feed the TWA3A primary. This finding is in contrast to most numerical simulations, whichpredict the secondary should be the dominant accretor in a binary system. Ourresults may be consistent with a model in which the precession of an eccentriccircumbinary disk gap alternates between preferentially supplying mass to theprimary and secondary.

Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary